1. Field of the Invention
Embodiments of the present invention relate to a keyboard apparatus for an electronic keyboard musical instrument, such as an electronic organ, an electronic piano, a portable electronic keyboard apparatus, and the like.
2. Description of Related Art
U.S. Pat. No. 4,512,234 describes a keyboard apparatus for an electronic keyboard musical instrument that has a frame, at least one key rotatably supported by the frame so that the key is movable about a rotation fulcrum of the key, and a mass member (weight) disposed in the interior of the key. The mass member is disposed in the interior of the key at a place remote from the rotation fulcrum of the key and close to a front end of the key (which is adjacent an area where a player depresses the key).
By adding the mass member at a location closer to the front end of the key, a moment of inertia of the key is increased and thus the key touch feeling (the feeling of good resistance) sensed by the player is improved.
However, in order to obtain a good key touch feeling by increasing the moment of inertia of the key in the conventional keyboard apparatus, a relatively heavy mass member has to be added within the key, and such a measure causes various problems.
For example, the heavier the mass member, the larger the volume of the mass member. Therefore, a relatively large space has to be provided within each key and thus the degree of freedom in designing the keys and the structure around the keys is substantially restricted. As a result, reducing the size of a keyboard apparatus is difficult.
Also, when the mass member is heavier, the frame that supports the mass member must be accordingly stronger to resist the impact force that is generated when the key is depressed. As a result, the entire weight of the musical instrument increases, making it difficult to transport the musical instrument. Also, heavy packaging is required for protecting the musical instrument from impact forces that may be generated during transportation, resulting in a higher cost.
The heavier mass member is more expensive to produce, and there is extra cost incurred for securely and strongly mounting the heavy mass member to the key so that the mass member does not fall off the key during intense performances of the musical instrument.